Zool— Vol. I.] BANCROFT— CHEL YOSOMA PRODUCTUM. 



323 



Dimensions of 

 Disk. 



Number of 

 Tentacles. 



6x4 



Il8 



10.5 x 6 



174 



13 x 11. 5 



480 



23 x 18 



142 



27 X 22 



214 



30 X 22 



123 



They are arranged in from two to four concentric rows, 

 the largest ones being situated on the outer side, and the 

 tentacles in adjacent rows alternating with each other in 

 position. The tentacles are often considerably smaller and 

 the rows fewer on the sides of the circle than anteriorly and 

 posteriorly. 



There is but one peripharyngeal band present, and since 

 this connects with the edges of the endostyle and the epi- 

 branchial groove, it evidently corresponds to the outer of the 

 two bands usually encountered. It is ciliated over its whole 

 surface, and in some preparations appears to fuse with the 

 lips of the dorsal tubercle. However, sections and the best 

 dissections show that it extends posteriorly to the orifice of 

 the tubercle to join the edge of the epibranchial groove. 



Little remains to be added to Drasche's account of the 

 relations of dorsal tubercle, hypophysial gland, epibranchial 

 groove, and ganglion. His excellent figure of these organs 

 represents a good average condition of my specimens, 

 except that the ganglion usually has five nerves extending 

 from it posteriorly, and that the hypophysial duct in all of 

 the individuals I examined extends along the left edge of 

 the gland, so that the tubules enter it from the right side 

 only. The shape and positions of these organs is remark- 

 ably constant. They are all placed a little to the right of 

 the median line joining the two orifices, exactly as in 

 C. macleayanum x , and their relations to each other were 

 always found to be exactly as in Drasche's figure. 



1 Drasche, who states that in this species the dorsal lamina is on the left of the median 

 line, evidently does not understand Kschricht's figures. 



